source: http://www.securityfocus.com/bid/10336/info
A vulnerability has been identified in multiple products from multiple vendors that may allow a remote attacker to create or modify arbitrary files; these issues relate to the processing of URI requests via various protocol handlers including telnet, rlogin, ssh and mailto.
The vulnerability presents itself because applications fail to validate URI input; if a '-' character precedes the host name it is possible to pass options to an application that handles the protocol.
Successful exploitation of this issue may allow a remote attacker to create or modify arbitrary files, resulting in a denial of service condition in the browser. The attack would occur in the context of the user running the vulnerable browser.
telnet://-fFileName
telnet://-nFilename